As [1]} point out, the models of [2]},
which are an application of those of [3]} to the planetary regime,
are premised on the assumption that, as for CTTSs, the H \(\alpha \)  emission
originates in the column(s) of gas accreting onto the planet.
Because the heating mechanism of these columns is highly unknown [4]}, these models are parametrised by a maximal temperature \(T_{\rm max}\)  in the column. [2]} do not consider emission from the post-shock region, which is appropriate for the stellar case.
Thus in [6]}, [1]}, [8]}, and this work, we are exploring a complementary approach. Namely, we are calculating the emission of H \(\alpha \)  and other lines by the postshock gas,
showing that it can be a detectable source,
and investigating here the absorption by the accreting material.
